Manga by author Asano Inio - Status ongoing

Large mysterious alien ships have been looming above Japanese towns for three years, filling the sky Everything changed three years ago. And yet, nothing has changed. No weapon used against the invaders' ships had any success, beyond destroying part of japan and leaving its economy in shambles. JSDF is fighting a guerrilla battle against the aliens all over Japan. America is joining the 'war' effort with more aggressive tactics, dividing Japan over the pacifist principle laid out in Art9. of their constitution. But this may just be the mundane story of young middle schoolers. "No matter what happens, I won't back down. At least not until this world filled with lies and deceit crumbles away. (...) The real threat to humankind is not invaders, but me."

Am I "necessary" in this world? What is the true nature of the person called "Muzina" who flies in the sky with a sword on her back in the midst of ordinary life? What is man, what is society, what are human rights, and what is happiness?

A young assassin girl armed with a katana is hunting down her targets in a busy metropolitan city named Tsukumo.